Control of call delivery and call forwarding of telecommunication connections, especially in multi-device configurations

ABSTRACT

The invention relates to a method and a system for controlling an arrangement of a configuration comprising two or more user devices (multi-device configuration) of telecommunication user devices in a public telecommunication network. According to the invention, the supplementary services of the public telecommunication network associated with the first user device or with an identification chip connected to the first user device are activated in such a manner that changes of the supplementary services are effective in the other user devices or the identification chip connected to the respective additional user device of the multi-device configuration at the same time or with a temporal delay. In this manner, when one or more parallel calls are switched to one or more user devices of the multi-device configuration, before delivery of the call, the kind of the call request resulting in a reservation of resources required for completing the call, the system states of the user devices to be called or of or of the identification chips connected to the user devices and the exchange devices involved therein are determined using an intelligent call control and the call can be delivered in a resource-saving manner.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of U.S. application Ser. No. 10/595,332,filed Dec. 15, 2006, entitled CONTROL OF CALL DELIVERY AND CALLFORWARDING OF TELECOMMUNICATION CONNECTIONS, ESPECIALLY IN MULTI-DEVICECONFIGURATION, which application is related to and claims the benefitunder 35 U.S.C. §119 and 35 U.S.C. §365 of International Application No.PCT/EP2004/011238, filed Oct. 8, 2004, the disclosures of which arehereby incorporated by reference.

The invention relates to the control of call forwarding and calldelivery in telecommunications networks, especially in cellular phonesystems.

Background and Problem Definition

Today's cellular phone networks use various procedures to enable a userto use multiple end devices (the so-called twin-card and multi-cardproducts). This type of product configuration may result, for example,from the parallel use of mobile end devices, a car telephone and anorganizer. In this scenario, one or several end devices are activated atthe same time for outgoing and incoming calls under a uniform number. Inconfigurations with several simultaneously active end devices, anyincoming connection requests occurring under a uniform number aresignaled in a parallel manner to the various end devices of thesubscriber.

The disadvantage of the existing procedures for such parallel calldelivery results from the uncertainty of the status of the end devices(switched off, technically not reachable, busy). This uncertainty maycause:

-   -   Unnecessary occupancy of cellular and land-based network        resources for attempts to connect that are actually unnecessary    -   Network services such as call forwarding to be executed in the        network area of the end device being called, which may lead to        partially undesired product scenarios and, in particular, to the        unnecessary use of network resources, and to substantial        additional costs for net operators and end customers.    -   Network services, such as call forwarding, depend on data        records that are separately assigned to each end device within        the network. Since these data records are not automatically        synchronized, the result is a different call behaviour depending        on which particular end device is being used and/or a        substantial cost for the user to manually synchronize the end        device data records. Furthermore, the user's selection options        for the settings of the network services must be restricted in        order to guarantee the correct network behaviour during the        delivery of parallel calls.

EP 0 711 090 A2 discloses a method to control a configuration oftelecommunication end devices comprising an arrangement of two or moreend devices (multiple-device configuration) in a publictelecommunication network. A number of subscriber identification chipsshare one single subscriber identification number.

U.S. Pat. No. 5,708,809 A describes a method to update the programstructure of a modular communication facility, which consists of severalmodules connected to each other through a bus. Upon the commencement ofoperation or a change in the configuration, the program structure isautomatically updated separately in each module.

EP 0 740 482 A1 relates to a telephone management system in the form ofa separate processor set up with the subscriber, which enables theconnection of a number of subscriber's end devices, such as cellularphone, cordless telephone, answering machine, etc. When an incoming callarrives, the processor forwards it to the momentarily “active” anddevice.

WO 01 0708 A1 discloses an automatic call distribution system similar tothe one of EP 0 740 482 A1 with the difference that, here, thedistribution of calls to connected end devices is performed by a networkelement of the communication network.

Therefore, the technical task of the present invention is to propose amethod and a system configuration that will guarantee a networkresource-saving control of end devices arrayed in a multiple-deviceconfiguration and, at the same time, to provide the user with a centralcontrol for all system behaviour.

This technical task is resolved by using a special control circuit andthe associated process according to the characteristics of the inventionclaims, the disclosure of which we herewith make reference.

Advantages of the Method

-   -   Optimal use of network resources for the design of        telecommunication connections, especially in cases that involve        call forwarding and parallel call attempts to several end        devices assigned to a single number.    -   Simple synchronization of a subscriber's features with respect        to a public cellular phone network, which the subscriber would        want to set up and call up as a one-time procedure in the        several end devices assigned to him.

Scope of Application

The basic idea of the invention relates to telecommunications networksin general. From the current point of view, a possible application topublic cellular communication networks (for example, according to theGSM standard) is interesting; however, the application is not limited tothis area.

In this document, when we speak of end devices in connection withcellular (mobile) telecommunications, in addition to the end deviceitself, we understand also a combination of an end device and aconnected identification chip (for example, GSM SIM, UMTS USIM, etc.) inall of the various versions that one might find in both existing andfuture cellular phone networks.

Technical Basis of the Method

The method uses the technology and network protocols according tointernational telecommunications standards, especially GSM/UMTS, and—inthis case—particularly those that accord with GSM CAMEL and MAPstandards. The functioning logic of the method is based on a centralservice node and a service database that communicates with and controlsthe switching and the mobility/profile databases of the subscribers tothe cellular telecommunications network.

A typical implementation of such a base is represented by theIntelligent Network Technology according to CCITT Q12XX Series (See alsoETSI CORE INAP protocol according to ETS 300 374, ETSI GSM CAMELprotocol 03.78) in conjunction with GSM MSC and GSM HLR.

DESCRIPTION OF THE METHOD

In the subsequent text, we describe the invention-underlying idea usingan example design without, however, limiting the idea's universalapplicability.

FIG. 1 shows a schematic representation of the network elements anddevices involved in the invented method.

FIG. 2 shows a schematic process flow of the synchronization of thesubscriber mobility/profile databases.

Description of the Network Elements Used in FIG. 1:

The individual blocks represent the following devices:A): Switching facility of a public network (for example, GSM MSC: mobileswitching center)Ba/b): Intelligent call control in a public network with an integratedor remote database for controlling the logic and subscriber data (forexample, IN SCP/SMP, service control point/service management point)Ca/b/c): Mobility/profile databases of the public network with locationinformation and feature profiles of the cellular phone subscriber (forexample, GSM HLR, home location register)D1/D2/D3): Switching facility of the public network (for example, GSMMSC)B10/B20/B30): Mobile end devicesE): Forwarding target

Several mobile end devices B10, B20, B30 (main and subsidiary devices)of a subscriber are assigned a single common subscriber's number in thedatabase Bb of a central call control system. Each end device isoperated, in a well-known manner, with an identification chip, which isalso called or referred to as a subscriber identification module, SIMcard, GSM SIM, UMTS, or USIM. The identification chip stores, amongother things, subscriber data that are required to access the cellularphone network and to use its services.

First, the subscriber sets up the features (such as call forwarding) forthe main device B10. The corresponding settings for the subsidiarydevices B20 and B30 are not set and the subscriber cannot change them.As will follow from the subsequent explanation, as a matter of fact, nocorresponding settings are required for the subsidiary devices.

If the switching facility A receives a call for the subscriber under thesubscriber's number common to all his end devices, such a call shallinitiate a polling of the subscriber's database Ca, which then—based onthe subscriber data, which is set up accordingly—initiates the pollingof the central call control system B.

This central call control system contains, in an assigned database,information related to devices B10, B20, B30, which are assigned to theparticular subscriber's number. The call control system B thendetermines the status of the assigned end devices in themobility/profile databases Ca, Cb and Cc of the subscribers to becalled. At the same time, the status of the subscribers to be called isalso being polled in the location switching centers D1, D2, D3. Based onthis information, and using a corresponding control circuit in the callcontrol system B, it is determined whether it makes sense to call theend devices in the network, or to immediately forward or release theincoming call. If—according to the rules stored in the call controlsystem—the end devices are to be called, the call control system Brequests that call switching facility A continue the call setup, whileparallel call attempts to multiple end devices B10, B20 and B30 can beperformed. At the same time, the call control system instructs theswitching facility A to report the unsuccessful end of these call setupattempts to call control system Ba. Normally, upon reaching certainconditions (not available, no calls accepted within the call interval),incoming calls are forwarded in the location switching facilities D1,D2, D3 of the subscriber on the basis of the profile of the calledsubscriber stored in the mobility/profile database Ca, Cb, Cc. In orderto avoid this undesired effect, the call control system instructs thelocation switching facility D1, D2, D3 of the subscriber, by means of asuitable signal, to suppress call forwarding. If in the further courseof action no connection is established, because, for example, the enddevices being called are not reachable or the subscriber does not acceptthe call, a negative acknowledgement shall be sent back to the callcontrol system B. Based on this information and on the polling of thesubscriber's profile in the main end device B10, which is used for allend devices, the call control Ba determines the reaction desired for thefurther course of action. This can be the release of the connection orthe forwarding of the call to a new target E. At this point, the callcontrol causes the call switching facility to trigger the correspondingfunctions and ends the control.

The subsequent example illustrates this process while describing theindividual process steps 0 to 17 as represented in FIG. 1.

0) Setup of the subscriber's profile (especially of the desired callforwarding behaviour) by the subscriber on end device B10 in theassigned profile database Ca at any time before the subsequentlydescribed process;1) An incoming call to the uniform number of the particular subscriberarrives at the switching facility A;2) Determination of the subscriber's location, for example, within therange of the switching facility D1, and of the subscriber's profile inthe mobility/profile database Ca by the switching facility A;3) Polling of the call control Ba by the switching facility A, triggeredby the polled subscriber's profile;4 a/b/c) Polling of the status of the end devices being called in themobility/profile databases Ca, Cb, Cc by the call control B;5 a/b/c) Polling/communication of the status of the end devices beingcalled B10, B20, B30 in the switching facilities D1, D2, D3 in whoserange the end devices are located;6 a/b/c) Communication of the status of the end devices being calledB10, B20, B30 to the call control Ba.

Afterwards, further steps are determined according to the call controlalgorithm stored in the call control system B (See Table 1). In thepresent example, the end device B30 has been reported by the locationswitching facility D3 as being unreachable. Thus, a call attempt withthe corresponding use of the communication resources could beeliminated. The end devices B10, B20 have been reported to be free.

7 a/b Initiation of call attempts to the “free” end devices B10/B20 ofthe same subscriber;8 a/b) Polling of the information necessary for call setup in thesubscriber's mobility/profile databases Ca, Cb;9 a/b) Polling/Communication of information required for call setup inthe subscriber switching facilities D1, D2 that serve the end devicesB10, B20;10 a/b) Communication of the information necessary for call setupbetween the switching facility A and the mobility/profile databases Ca,Cb;11 a/b) Call delivery with occupancy of the stationary/cellular phonenetwork resources, for example, through a transit network and thecellular phone network;12 a/b) Unsuccessful call setup to the end devices B10/B20 (for example,due to technically unreachable end devices, because the subscriber doesnot respond, or because the subscriber rejects the call);13 a/b) Communication of a message relating the unsuccessful call setupto switching facility A, release of the network resources;14 a/b) Communication of a message relating to the unsuccessful callsetup from the switching facility A to the intelligent call control B;15) Determination of the settings planned for this case, for example,call forwarding, in the profile database Ca of the main subscriber B10and deriving of further behavior by the call control system B.16) Initiation of call forwarding17) Direct call setup by the network switching facility to theforwarding target E

Thus, a connection with the corresponding line occupancy from theoriginal switching facility A to the location switching facility D1, D2of the subscriber's and further to the final forwarding target E, whichis otherwise normal for such call forwarding processes, can beeliminated.

The following Table 1 provides an example of the process by which thesuitable behavior of the call control Ba in the network element B isdetermined (See step 6 above): Using the status determined for the enddevices B10/B20/B30 (Here: Table 1, row 3: Idle, Idle, NRc) (Steps 4through 6), a decision is made on the further course of the connectioncontrol.

TABLE 1 Response after completion of the Nb B10 1) B20 1) B30 1) statuspolling Note 1 Idle Idle Idle Call B10/B20/B30 2) 2 Idle Idle Busy Callforwarding according to subscriber profile 3 Idle Idle NRc Call B10/B202) 4 Idle Idle NP Call B10/B20/B30 2) 5 Idle Busy Idle See row 2 6 IdleBusy Busy See 2 7 Idle Busy NRc See 2 8 Idle Busy NP See 2 9 Idle NRcIdle Call B10/B30 2) 10 Idle NRc Busy See 2 11 Idle NRc NRc Call B10 2)12 Idle NRc NP Call B10/B30 2) 13 Idle NP Idle Call B10/B20/B30 2) 14Idle NP Busy See 2 15 Idle NP NRc Call B10/B20 2) 16 Idle NP NP CallB10/B20/B30 2) 17 Busy Idle Idle See 2 18 Busy Idle Busy See 2 19 BusyIdle NRc See 2 20 Busy Idle NP See 2 21 Busy Busy Idle See 2 22 BusyBusy Busy See 2 23 Busy Busy NRc See 2 24 Busy Busy NP See 2 25 Busy NRcIdle See 2 26 Busy NRc Busy See 2 27 Busy NRc NRc See 2 28 Busy NRc NPSee 2 29 Busy NP Idle See 2 30 Busy NP Busy See 2 31 Busy NP NRc See 232 Busy NP NP See 2 33 NRc Idle Idle Call B20/B30 2) 34 NRc Idle BusySee 2 35 NRc Idle NRc Call B20 2) 36 NRc Idle NP Call B20, B30 2) 37 NRcBusy Idle See 2 38 NRc Busy Busy See 2 39 NRc Busy NRc See 2 40 NRc BusyNP See 2 41 NRc NRc Idle Call B30 2) 42 NRc NRc Busy See 2 43 NRc NRcNRc See 2 44 NRc NRc NP Call B30 2) 45 NRc NP Idle Call B20/B30 2) 46NRc NP Busy See 2 47 NRc NP NRc Call B20 2) 48 NRc NP NP Call B20/B30 2)49 NP Idle Idle Call B10/B20/B30 2) 50 NP Idle Busy See 2 51 NP Idle NRcCall B10/B20 2) 52 NP Idle NP Call B10/B20/B30 2) 53 NP Busy Idle See 254 NP Busy Busy See 2 55 NP Busy NRc See 2 56 NP Busy NP See 2 57 NP NRcIdle Call B10/B30 2) 58 NP NRc Busy See 2 59 NP NRc NRc Call B10 2) 60NP NRc NP Call B10/B30 2) 61 NP NP Idle Call B10/B20/B30 2) 62 NP NPBusy See 2 63 NP NP NRc Call B10/B20 2) 64 NP NP NP Call B10/B20/B30 2)A Explanations of the notes in the table: 1) Subscriber status: Busy NRc= Not reachable Idle NP = Not provided 2) Connection setup to thedetermined end devices is initiated.

A further improvement of the process is achieved, if the call control Bnot only uses the profile data of the mobility/profile database Ca of amaster chip card (which is the SIM card of the main end device) for thecontrol, but this data is also synchronized with the mobility/profiledatabases Cb, Cc of the other SIM cards. This results in the advantagefor the user in that, using any of his end devices B10, B20, B30, he canpoll the status of the assigned mobility/profile database Ca, Cb, Cc,and always receives the same information about the status of hisfeatures (for example, call forwarding). FIG. 2 shows an exemplaryimplementation of this synchronization.

The subscriber activates on one of his end devices, for example, on enddevice B20, call forwarding. The setting performed by the subscriber iscommunicated by end device B20, or by the SIM card operated with thedevice through the switching facility D2 and the correspondingsubscriber mobility/profile database Cb, and stored there. Thesubscriber mobility/profile database Cb informs the intelligent callcontrol B about the setting (modification) of the subscriber profileperformed by the subscriber. The call control B synchronizes theperformed setting with the mobility/profile databases Ca, Cn that areassigned to the other SIM cards or end devices B20, B30.Possibilities of Application of the Method According to this Inventionand Tips on its Execution

a) Using an end device and its common functions, the subscriber to apublic cellular phone network can normally activate the features of hispublic network assigned to the end device (or rather to itsidentification chip—such as GSM-SIM, UTS-USIM—that is connected to suchend devices) in such a manner that this change has a synchronous effectalso on other features stored in the same network and assigned to otherdevices (or rather to identification chips connected to them) of thesame subscriber. This occurs in that an intelligent call control pollsthe profile of the particular end device and applies it, for example, toone or more associated end devices to control their features during acall setup.

b) The network resources (switching, lines) required to switch one ormore parallel calls to one or more end devices of a user are minimizedin that, before the call is delivered with the resulting necessaryoccupancy of the required resources, polling the correspondingmobility/profile databases and also the switching facilities, in whichthe end devices are located, first an intelligent call control derivesthe system status (for example, busy, free, not reachable) of the enddevices to be called and derives from it the optimal call delivery,during which only call attempts that promise success are initiated.

c) The network resources (switching, lines) required for the switchingof a call forwarding in the public cellular phone network are minimizedin that, before the call is delivered, polling the correspondingdatabase that stores the assigned feature profile and also the switchingfacilities, in which the end device is located, first an intelligentcall control derives the system status (for example, busy, free, notreachable) of the end device to be called and—if possible—immediatelyinitiates a call forwarding process in accordance with the determinedsystem status of the end device (free, busy, not reachable) and thesettings of the end device, i.e., without setting up a line to the enddevice called. If it is possible to derive from the determined systemstatus that an end device is free to receive a call, first the call isdelivered, however, in such a manner that—should it not be accepted (forexample, because the end device is technically not reachable, thesubscriber does not respond, the subscriber rejects the call), theoccupied line is again released up to the origin of the connection and,depending on the end device status determined from the unsuccessful callattempt and the previously determined settings of the end device forcall forwarding functionality, a direct connection is established to adesired call forwarding target.

d) Use and combination of the above methods to optimize the networkresources used and the customer-relevant system behaviour for theexecution of parallel call attempts of end devices assigned to a userinitiated by a call. Here, based on the evaluation of the systemstatuses of all parallel end devices being called, the call forwardingis initiated in the original switching facility by a central control.

1. A method to control a configuration containing the array of two ormore telecommunication end devices (multiple-device configuration) in apublic telecommunication network, characterized in that upon theactivation of changes in the features of the public telecommunicationsnetwork assigned to a first end device or rather to an identificationchip connected to the first end device, these changes in the featuresare activated, at the same time or with a temporal delay, also in theother end devices or rather in the identification chips connected to theparticular end devices of the multiple-device configuration, wherein anintelligent call control polls a mobility/profile database for theprofile of the first end device or rather of an identification chipconnected to the first end device and, at least partially, uses it tocontrol the features during the call setup to at least one more enddevice.
 2. A system in a public telecommunications network for anoptimal control of the call delivery and/or call forwarding in amultiple-device configuration that consists of at least two end devicesof a telecommunications system, characterized in that a memory unit isprovided, in which the system statuses of the end devices involved inthe multiple-device configuration are stored, at least partially, andthat intelligent process control is provided that is connected to theindicated memory unit and to the units to be controlled.